Field of the Disclosure
The embodiments described herein relate to power charge connectors for downhole setting tools and methods of using the same.
Description of the Related Art
A downhole setting tool may use a power charge to set a device within a wellbore. The power charge is detonated to generate the force required to set the device. For example, the force from the detonated power charge may move a piston causing the setting of the device. The power charge of the downhole setting tool may be used to set various devices in a wellbore as would be appreciated by one of ordinary skill in the art. For example, a downhole setting tool with a power charge may be used to set bridge plugs, cement retainers, packers, and various other downhole devices.
An electrical signal is typically sent down a conduit to the setting tool to actuate a primary igniter in the firing head of the setting tool. The actuation of the primary igniter is used to detonate the power charge, which is typically located downhole from the primary igniter in a chamber connected to the firing head via a cartridge seat. The downhole setting tool may include a secondary igniter that is used to detonate the power charge upon the actuation of the primary igniter. The primary igniter often comprises black powder (e.g., gun powder, a mixture of sulfur, charcoal, and saltpeter) that is ignited from the electrical signal.
It has been recognized that it would be beneficial to increase the reliability with which the power charge of downhole setting tools detonates and sets the downhole device. For example, on Jan. 13, 2017, Applicant filed U.S. patent application Ser. No. 15/406,040 entitled “SETTING TOOL POWER CHARGE INITIATION” that is directed to devices and methods for initiating or setting off a power charge, which is incorporated by reference herein in its entirety.
FIG. 6 shows an embodiment of known conventional downhole setting tool 200. The setting tool 200 may be the E-4 packer setting device which is available commercially from Baker Hughes Incorporated of Houston, Tex. The setting tool 200 includes a firing head 210 connected to an adapter 230, which is also referred to as a cartridge seat. The adapter 230 houses the primary igniter 220. The E-4 packer setting device also includes a secondary igniter 235 housed within the adapter 230, which is ignited by the actuation or ignition of the primary igniter 220. The actuation of the primary igniter 220 pushes the secondary igniter 235 towards the power charge 250 as shown by secondary igniter 235′ shown in dash.
The power charge 250 includes an outer housing 255 and is positioned within a chamber 245 of a housing 240 connected to the firing head 210. The downhole side of the housing 240 is connected to a sub 280 that is connected to the device (not shown) to be set within the wellbore. The sub 280 provides communication with an actuation mechanism, such as a piston, configured to move and set the device upon the detonation of the power charge 250 as would be appreciated by one of ordinary skill in the art. The downhole end 252 of the power charge 250 is inserted into the chamber 245 of the housing 240 and the power charge 250 and the power charge 250 is pushed into the chamber 245 until the downhole end 252 is positioned within the sub 280. The housing 240 containing the power charge 250 is then connected to the firing head 210 and the adapter 230. The uphole end 251 of the power charge 250 includes an igniter 260 that helps to detonate the power charge 250 upon the ignition of the primary igniter 220 and the secondary igniter 235. As used herein, the uphole end refers to the end of an object that is closer to the opening of a wellbore at the surface in comparison to the other end of the object, referred to herein as the downhole end.
Conventional downhole setting tools that include power charges are very reliable and are used to set a large number of devices in a wellbore. However, even if conventional setting tools are 99% reliable, the removal of one setting tool and device out of one hundred from the wellbore is a potentially costly and time consuming operation. As the downhole tool 200 is run into the wellbore the power charge 250 may become misaligned with the primary igniter 220 and/or secondary igniter 235 potentially causing the power charge 250 to not detonate when the igniter(s) 220, 235 are actuated. For example, as the tool 200 traverses around a lateral in a wellbore the secondary igniter 235 may fall into a cavity as shown as 235′ in FIG. 6 becoming misaligned with the power charge 250. A secondary igniter 235′ in a misaligned positioned may fail to detonate the power charge 250. Other disadvantages may exist.